<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<dl id="app">
    <dt>Java</dt>
    <dt>JavaSE</dt>
    <dt>JavaEE</dt>
</dl>


<script>
    var dl = document.getElementById('app');    //dl就是获取到的app节点
</script>

</body>
</html>